Thank you for the specifics! I think I see what you are thinking. Both batteries would provide the full 'battery part' of the consumption for a 24hr cycle - its just that the LTO could provide short bursts (high consumption during parts of the day) and the 18650 would have a smoother cycle - i.e. steady power to recharge the LTO over a 24hr period.

This would mean
1) The LTO would have to be large enough to provide the required 'battery consumption' for the cycle
2) The 18650 would still need to provide the 'battery consumption' - its just that it could do a shallower DOD since its spaced out over 24hrs.

In my case, the LTO would have to be huge (20kwh or more) and that defeats the purpose $ wise for me.